I've towed our trailer about 14k + miles and usually keep it in Drive with Eco OFF. Only time I've used the paddles is to keep the RPM's around 3kish when on a grade if the RPM's are low.
2014 GC Overland 4x4, 3.0CRD, ATG, ORAII ("Smiffy")
2015 Lance 1685 Travel Trailer "#4"
2011 Kia Optima EX-L ("MC"
2003 BMW R1150RT "Darth"